FASLG and intervertebral disk degenerative disorder: The characteristic of IDD is that the dysfunctional FASL reduce the expression level of FASL and unbalance the interaction between NP cells and immune cells, leading to the expression of certain regulatory factors that may play a role in this process [33], such as hsa_circ_0001658 and hsa-miR-181c-5p in this study.